Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.

In a large bowl, combine flour, cocoa powder, baking powder, cinnamon, cloves, nutmeg, and sugar.

Add the shortening and mix until crumbly.

Stir in eggs, milk, and vanilla. Mix until well blended. Dough should be sticky but thick.

Fold in walnuts and mini chocolate chips if using.

Drop by heaping tablespoons onto prepared baking sheets, shaping into round mounds.

Bake for 12–15 minutes, or until cookies are set and slightly firm. Remove and let cool.

For the icing, whisk powdered sugar, milk, and vanilla until smooth.

Dip the tops of the cooled cookies into the icing and place on a rack to set. Add sprinkles if desired.